The Wikipedia article for Theseus ends its introduction with this:
As the subject of myth, the existence of Theseus as a real person has
not been proven, but scholars believe that he may have been alive
during the Late Bronze Age possibly as a king in the 8th or 9th
This assertion is based on Classical Mythology Tenth Edition. Quoting ...
Yes, she did know.
There are at least two ancient sources which make this explicit, the first being Nonnus' Dionysiaca, which places the reign of Perseus in Argolis during the time that Perseus' half-brother the wine-god Dionysus is concluding his epic tour of Greece. At the end of Dionysus' itinerary is the region of Argolis, one of whose major cities is ...